1. Field of the Invention
The present invention relates to a fusing apparatus, and more particularly to a fusing apparatus that fuses a toner image formed on a recording member, and an image forming apparatus including the fusing apparatus.
2. Description of the Related Art
Conventionally, in order to reduce power consumption in a fusing apparatus, for example, as described in Document 1 (Japanese Laid-Open Patent Publication No. 09-080952), a configuration is proposed in which a release layer provided on a surface of a heat member such as a heat roller is made of a material with a relatively low thermal emissivity and a relatively high thermal conductivity. With this, it is intended to suppress the quantity of heat radiated from the surface of the heat member.
In such a fusing apparatus, the surface temperature of the heat member affects the behavior of fusing of a toner image to a recording member, which in turn affects image formation quality on the recording member. Thus, control of the surface temperature is important. Note that in recent years, in a fusing apparatus such as that described above, in order to avoid the wearing away of the surface of the heat member, it has become more common to detect the surface temperature of the heat member by a non-contact sensor such as a thermopile.
In order to avoid the wearing away of the surface of the heat member, etc., the case of detecting the surface temperature of the heat member by a non-contact temperature sensor is considered. Meanwhile, when a release layer with a relatively low thermal emissivity is formed on the surface of the heat member, a change in the surface temperature of the heat member is difficult to be reflected in the amount of infrared rays emitted from the surface of the heat member. Due to this, when a conventional fusing apparatus attempts to detect the surface temperature of a heat member by a non-contact temperature sensor, a change in the surface temperature is difficult to be reflected in a change in detection output from the sensor, causing concerns about a reduction in the accuracy of temperature detection by the sensor.